Robotic distal ureterectomy for high-risk distal ureteral urothelial carcinoma: a retrospective multicenter comparative analysis (ROBUUST 2.0 collaborative group).

BACKGROUND: The role of kidney-sparing surgery in patients with high-risk upper urinary tract urothelial carcinoma is controversial. The present study aimed to assess oncological and functional outcomes of robot-assisted distal ureterectomy in patients with high-risk distal ureteral tumors. METHODS: The ROBUUST 2.0 multicenter international (2015-2022) dataset was used for this retrospective cohort analysis. High-risk patients with distal ureteral tumors were divided based on type of surgery: robot-assisted distal ureterectomy or robot-assisted nephroureterectomy. A survival analysis was performed for local recurrence-free survival, distant metastasis-free survival, and overall survival. After adjusting for clinical features of the high-risk prognostic group, Cox proportional hazard model was plotted to evaluate significant predictors of time-to-event outcomes. RESULTS: Overall, 477 patients were retrieved, of which 58 received robot-assisted distal ureterectomy and 419 robot-assisted nephroureterectomy, respectively, with a mean (±SD) follow-up of 29.6 months (±2.6). The two groups were comparable in terms of baseline features. At survival analysis, no significant difference was observed in terms of recurrence-free survival (P=0.6), metastasis-free survival (P=0.5) and overall survival (P=0.7) between robot-assisted distal ureterectomy and robot-assisted nephroureterectomy. At Cox regression analysis, type of surgery was never a significant predictor of worse oncological outcomes. At last follow-up patients undergoing robot-assisted distal ureterectomy had significantly better postoperative renal function. CONCLUSIONS: Comparable outcomes in terms of recurrence-free survival, metastasis-free survival, and overall survival between robot-assisted distal ureterectomy and robot-assisted nephroureterectomy patients, and better postoperative renal function preservation in the former group were observed. Kidney-sparing surgery should be considered as a potential option for selected patients with high-risk distal ureteral UTUC.

Decisional and prognostic impact of diagnostic ureteroscopy in high-risk upper tract urothelial carcinoma: A multi-institutional collaborative analysis (ROBUUST collaborative group).

BACKGROUND: Diagnostic ureteroscopy (URS) with or without biopsy remains a subject of contention in the management of upper tract urothelial carcinoma (UTUC), with varying recommendations across different guidelines. The study aims to analyse the decision-making and prognostic role of diagnostic ureteroscopy (URS) in high-risk UTUC patients undergoing curative surgery. MATERIALS AND METHODS: In this retrospective multi-institutional analysis of high-risk UTUC patients from the ROBUUST dataset, a comparison between patients who received or not preoperative URS and biopsy before curative surgery was carried out. Logistic regression analysis evaluated differences between patients receiving URS and its impact on treatment strategy. Survival analysis included 5-year recurrence-free survival (RFS), metastasis-free survival (MFS), cancer-specific survival (CSS) and overall survival (OS). After adjusting for high-risk prognostic group features, Cox proportional hazard model estimated significant predictors of time-to-event outcomes. RESULTS: Overall, 1,912 patients were included, 1,035 with preoperative URS and biopsy and 877 without. Median follow-up: 24 months. Robot-assisted radical nephroureterectomy was the most common procedure (55.1%), in both subgroups. The 5-year OS (P = 0.04) and CSS (P < 0.001) were significantly higher for patients undergoing URS. The 5-year RFS (P = 0.6), and MFS (P = 0.3) were comparable between the 2 groups. Preoperative URS and biopsy were neither a significant predictor of worse oncological outcomes nor of a specific treatment modality. CONCLUSIONS: The advantage in terms of OS and CSS in patients undergoing preoperative URS could derive from a better selection of candidates for curative treatment. The treatment strategy is likely more influenced by tumor features than by URS findings.

Micronucleus formation in human keratinocytes is dependent on radiation quality and tissue architecture.

The cytokinesis-block micronucleus (MN) assay was used to assess the genotoxicity of low doses of different types of space radiation. Normal human primary keratinocytes and immortalized keratinocytes grown in 2D monolayers each were exposed to graded doses of 0.3 or 1.0 GeV/n silicon ions or similar energies of iron ions. The frequencies of induced MN were determined and compared to γ-ray data. RBE(max) values ranged from 1.6 to 3.9 for primary keratinocytes and from 2.4 to 6.3 for immortalized keratinocytes. At low radiation doses ≤ 0.4 Gy, 0.3 GeV/n iron ions were the most effective at inducing MN in normal keratinocytes. An "over-kill effect" was observed for 0.3 GeV/n iron ions at higher doses, wherein 1.0 GeV/n iron ions were most efficient in inducing MN. In immortalized keratinocytes, 0.3 GeV/n iron ions produced MN with greater frequency than 1.0 GeV/n iron ions, except at the highest dose tested. MN formation was higher in immortalized keratinocytes than in normal keratinocytes for all doses and radiation qualities investigated. MN induction was also assessed in human keratinocytes cultured in 3D to simulate the complex architecture of human skin. RBE values for MN formation in 3D were reduced for normal keratinocytes exposed to iron ions, but were elevated for immortalized keratinocytes. Overall, MN induction was significantly lower in keratinocytes cultured in 3D than in 2D. Together, the results suggest that tissue architecture and immortalization status modulate the genotoxic response to space radiation, perhaps via alterations in DNA repair fidelity.